Locking coupler for floor maintenance pad

ABSTRACT

A coupler is disclosed for coupling floor maintenance pads to a pad driven disc. The coupler has one part which is mounted to or from an integral part of the driver disc and a second part which snaps onto the first part for holding and centering a maintenance pad to a disc. A spring lock arrangement is provided for preventing the coupler from separating and comprises a spring clip carried by the retainer engageable with lip structure formed on an axially extending wall or flange forming part of the base part. The spring clip is held to the retainer by hub segments and axially spaced tabs which define slots for slidably receiving portions of the spring clip. The spring clips include a pair of elongate legs interconnected by a bridging segment on one end and a pair of finger engageable pressure pads on opposite ends by which the spring clip is squeezed to move corner segments carried by legs inwardly in order to disengage the lip structure thereby releasing the retainer from the base.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to apparatus for securing a pad to a rotary floor machine of the type used in floor maintenance, and more particularly, a “snap together” coupler for securing a pad to a rotating driver disc of a floor maintenance machine.

BACKGROUND OF THE INVENTION

Coupler devices are well known for centering and coupling a floor maintenance pad to a pad driver disc. The pad driver disc is rotated by the drive shaft of a power-driven floor maintenance machine. One example of such a coupling device is illustrated and described in U.S. Pat. No. 4,536,912.

A pad coupler device typically has two parts, one of which is secured to the pad driver and the other of which is removable and is used to secure the pad to the pad driver. Various methods for maintaining the engagement between the pad driver mounted portion and the retainer portion have been suggested for use in the prior art. For example, the two parts may have threaded portions which interengage in order to secure the retaining portion to the pad driven portion. An example of a threaded engagement is illustrated in U.S. Pat. No. 5,400,461.

Other coupling structures have also been disclosed in the prior art. For example, in U.S. Pat. No. 4,541,207, a “pull-apart” design is illustrated. In the construction shown in this patent, interengaging lips are used to releasably secure a “split-ring” retainer to a base. In the disclosed coupling device, friction and elasticity are relied upon to maintain engagement of the members.

Since the pads of a floor cleaning machine are replaced frequently due to wear or the need to use a pad with different abrasive characteristics, it is important that the retainer portion of the coupling device be easily released. In many of the prior art devices, release of the retainer from the base in order to release the pad from the pad driver can be difficult. In some constructions that provide easy release of the retainer, the coupling is not as reliable as desired.

U.S. Pat. No. 5,806,132, which is owned by the Assignee of the present application, discloses an example of a “snap-together” coupling device. The illustrated coupling device has retainer and base members that are easily released and the device has enjoyed commercial success. However, an improved coupling device is desirable.

DISCLOSURE OF THE INVENTION

The present invention provides a new and improved coupling device for securing a pad to a drive disc of a floor maintenance machine. In particular, the invention comprises a “snap together” coupling device which includes a base mountable coaxially to the drive disc, having an annular, axially extending flange or wall. A retainer is releasably engageable with the base and in particular, carries a retaining element having portions engageable with wall structure defined by the annular, axially extending flange defined by the base.

In the preferred and illustrated embodiment, the annular, axially extending flange defined by the base includes an internal undercut that defines a radially extending lip. In the illustrated embodiment, both the annular flange and the lip are continuous. The lip defines an engagement surface for portions of the retaining element that is carried by the retainer.

Preferably the retainer defines a hub-like structure which mounts the retaining element. The hub includes openings through which portions of the retaining element movably extend. These portions engage an underside of the lip defined by the base and resist separation of the retainer from the base.

In the illustrated embodiment, the retaining element in a retainer clip and the clip engagement portions define corner-like segments. These corner segments co-engage the underside of the lip when the retainer is installed on the base.

Preferably, these corner segments are located at distal ends of associated resilient support legs. The support legs are slidably held by the hub. In particular, the hub includes spaced apart, laterally extending hub segments/tabs which together define slots for receiving the legs of the retaining clip.

According to a feature of the invention, the retainer may define a lug which is also engageable with the underside of the lip defined by the base. In the illustrated embodiment, the engagement lug is supported by an associated lug support forming part of the retainer.

According to another feature of the invention, the resilient legs of the retaining clip are interconnected by a connecting segment. Distal ends of the legs terminate in actuating segments which are designed to receive finger pressure by an operator. Squeezing the actuating segments towards each other causes the corner segments of the retaining clip to move out of engagement with the lip defined by the base thus releasing the retainer from the base.

In the preferred and illustrated embodiment, the actuating segments, corner segments, resilient legs and connecting segment are integrally formed from suitably selected spring wire and thus define a spring clip.

According to another feature of the invention, both the base and retainer are molded from a suitable polymer.

The disclosed coupling device is easily separated when a floor maintenance pad, etc. needs to be replaced. In addition, the elimination of the central post of the prior art, opens up the central portion of the coupling device and allows cleaning fluids, etc. carried by the maintenance machine to be discharged onto the floor (through the coupling device) during the floor maintenance operation.

With the disclosed snap-together coupling device, machine pads can be easily removed and reinstalled onto a floor maintenance machine. To remove the retainer from the base, the legs of the spring clip are squeezed together (via the finger receiving segments) in order to move the corner segments of the spring clip inwardly and out of engagement with the lip forming part of the base. Once the corner segments disengage the lip, the retainer can be easily moved in an axial direction, out of engagement with the base. The machine pad is placed in position on the base and the retainer is then pushed back onto the base. The axially extending wall preferably includes a chamfered or cone-shaped end surface which urges the corner segments of the springs to move inwardly as the retainer is pushed into engagement with the base. The resilient legs of the spring clip urge the corner segments outwardly as the corner segments pass the lip and thus cause the corner segments to move outwardly to engage the underside of the lip.

Additional features of the invention will become apparent and a fuller understanding obtained by reading the following detailed description made in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a floor maintenance machine coupler of the present invention;

FIG. 1A is a top plan view of the maintenance machine coupler shown in FIG. 1;

FIG. 2 is an exploded perspective view of a coupler mounted to a floor maintenance machine;

FIG. 3 is a bottom plan view of the coupler shown in FIG. 1;

FIG. 4 is a side view of the coupler;

FIG. 5 is a cross-sectional view of the coupler as seen from the plane indicated by the line 5-5 in FIG. 3; and

FIG. 6 is a cross-sectional view of the coupler as seen from the plane indicated by the line 6-6 in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a pad coupler 10 for a floor maintenance machine is shown which has a base 12 and a retainer 14. As seen in FIG. 2, the base 12 is coaxially attached to a pad driver disc 16. A portion of the retainer 14 extends through a circular mounting hole 18 of a floor maintenance pad 20 and, as will be de-scribed, “snaps” onto the base 12. The coupler 10 centers and holds the pad 20 to the disc 16 when in its coupled state.

In the machine illustrated in FIG. 2, the pad driver 16 engages the upper surface of the pad 20 with a plurality of bristles which operate to drivingly engage the pad for a variety of floor maintenance operations such as polishing, burnishing, scrubbing and stripping. Each separate task requires a pad 20 with particular abrasive characteristics. Due to the “snap together” feature of the disclosed pad coupler, the retainer 14 is readily uncoupled from the base 12 to permit an operator to replace the pad 20.

The base 12 is preferably molded and includes a circular, axially extending wall or flange 22 (see FIG. 1). A circular flange 24 extends radially outwardly from the wall or axial flange 22. The radially extending flange 24 has a plurality of screw holes 26 formed in its surface for attaching the base 12 to the driver disk 16 with fasteners such as screws. Numerous holes 26 are provided in various patterns to make the base 12 compatible with many if not most of the conventional types of pad drivers 16, now on the market. A plurality of tines 28 is formed on the side of the flange 24 that faces away from the driver disk 16. The tines 28 project in the axial direction and pierce the pad 20) and hold it in position. The tines 28 also serve to inhibit the pad 20 from stretching outwardly during high speed operation due the influence of centrifugal force.

The retainer 14 includes a hub 32 and a radial flange 34. As will be described, the hub 32 of the retainer 14 is sized and configured to slidably fit within the axial flange 22 defined by the base 12.

Referring to FIGS. 1, 5 and 6, the axially extending flange or wall 22 of the base 12 includes an undercut indicated generally by the reference character 30. As seen best in FIGS. 5 and 6, the undercut 30 defines a lip 30 a that extends radially inwardly from an inside wall 22 a of the axial flange 22. An underside 30 b of the lip 30 a, defines an engagement surface engageable by retaining structure forming part of the retainer 14. As seen best in FIGS. 5 and 6, the axial flange 22 also defines a cone-shaped camming surface 36 and as will be described, facilitates engagement of the retainer 14 with the base 12.

In the preferred and illustrated embodiment, the wall 12 and associated lip structure 30 is continuous. Segmented or discontinuous axial flanges and lip structure are contemplated by the present invention.

Turning now to FIGS. 1, 5 and 6, the retainer 14 mounts a retaining element 40 and other structure which is engageable with the lip structure 30. When the lip 30 a is engaged by the element 40 and other structure, the retainer 14 is releasably held to the base 12.

In the preferred and illustrated embodiment, the retaining element is a locking or retaining clip 40 and the other structure is a lug 48 that is preferably molded and forms an integral part of the retainer 14.

Referring also to FIG. 3, the locking clip 40 is preferably formed from suitable spring wire and is loosely held within the hub 32 of the retainer 14. As seen best in FIG. 3, the spring clip 40 includes a pair of corner segments 40 a formed near the ends of associated, resilient, leg elements 40 b. The leg elements 40 b are interconnected by a bridging segment 40 c. In the illustrated embodiment, the retainer clip 40 is generally U-shaped. Distal ends of the legs 40 b terminate in associated circular/square shaped loops 40 d which define finger engageable pressure pads. As should be apparent from viewing FIG. 3, squeezing the pressure pads urges the locking legs 40 b towards each other, thus moving the corner segments 40 a inwardly. The spring clip 40 is configured such that the corner segments 40 b are urged outwardly when the pressure pads 40 c are released.

The corner segments 40 b extend through associated slots 50 formed in the hub 32. The hub 32 also includes two pairs of laterally extending segments 52 disposed on either side of an associated axially spaced tab 54. Each leg 40 b of the spring clip 40 is thus slidably captured between a pair of laterally extending segments 52 and the associated axially spaced tab 54 (shown best in FIGS. 1, 1A and 3). The bridging segment 40 c of the spring clip 40 is held in spaced apart slots 56, one of which is shown in FIG. 5.

The engagement of the spring clip 40 with the slots 56, the lateral segments 52 and the tabs 54 captures and maintains the spring clip 40 within the hub 32 of the retainer 14. The disclosed engagement allows sliding movement of the legs 40 b to enable the corner segments 40 a to be moved from an outward, engaged position at which the corner segments 40 a engage the underside 30 b of the lip 30 a of the base and a released position at which the corner segments 40 a are moved inwardly and are disengaged from the lip structure 30.

As seen best in FIG. 5, the locking lug 48 is positioned in substantially the same plane as the corner segments 40 a of the spring clip 40. Accordingly, when the retainer 14 is installed into the base 12, an underside 48 a of the lug 48 engages the lip surface 30 b of the base 12. The retainer 14 is thus held to the base 12 by means of the engagement between the lip structure 30 of the base and the corner segments 40 a of the spring clip 40 and the lug 48 that is preferably molded into the retainer 14.

The retainer 14 is easily disengaged from the base 12 by squeezing the loops 40 d of the spring clip 40 in order to move the corner segments 40 a inwardly and out of engagement with the lip 30. The disengagement of the corner segments 40 a allows at least a portion of the retainer 14 to be separated slightly to enable the disengagement of the locking lug 48 from the lip 30 resulting in the separation of the retainer from the base.

In the preferred and illustrated embodiment, the retainer 14 is easily reengaged with the base 12 by simply aligning the hub 32 of the retainer with the axial flange 22 and pushing the retainer 22 axially towards the base 14. The camming surface 36 defined by the axial flange 22 urges the corner segments 40 a inwardly to allow the segments to pass the lip structure 30. Once the corner segments 40 a move past the lip 30 a, the legs 40 b urge the corner segments 40 a outwardly so that they engage the underside 30 b of the lip 30, thus locking the retainer 14 to the base 12. The locking lug 48, forming part of the retainer 14, is supported by a resilient arm 48 b (see FIGS. 1 and 5) molded into the retainer 14, and it too, can move radially inwardly in order to pass by the lip structure 30.

It should be apparent that the disclosed locking coupler greatly facilitates the removal and reinstallation of a floor treatment pad onto a floor maintenance machine. The configuration and inter-engagement between the hub 32 and the axial flange 22 provides a self-centering feature which allows the operator to simply snap on the retainer 14 when replacing a floor treatment pad. Special tools or auxiliary fasteners are not needed.

In addition, a rather large central opening is defined by the coupler 10 that facilitates the flow of cleaning and other solutions from the floor maintenance machines onto the floor during machine operation. The cleaning efficiency of the machine is thus substantially improved over the prior art where cleaning solutions were fed through relatively small central openings or small holes in the coupler itself.

Although the invention has been described with a certain degree of particularity it should be understood that those skilled in the art can make various changes to it without departing from the spirit or scope of the invention as hereinafter claimed. 

1. A snap together coupling device for mounting a floor maintenance pad having a circular mounting hole, to a drive disc, on a power driven floor maintenance machine, the coupling device comprising: a) a base part mountable co-axially to the drive disc and having an axially extending flange, said flange defining a lip structure extending radially inwardly from an inner wall of said axial flange; b) a retainer part defining structure sized and configured to fit within said axial flange of said base; c) a retaining mechanism carried by said retainer part and including elements resiliently engageable with said lip structure whereby said base is inhibited from separating from said retainer.
 2. The apparatus of claim 1, wherein said axial flange is continuous.
 3. The apparatus of claim 2, wherein said lip structure is continuous.
 4. The apparatus of claim 1, wherein said retaining mechanism includes a locking lug engageable with said lip structure defined by said base.
 5. The apparatus of claim 1, wherein said retaining mechanism comprises a spring clip that defines corner segments near ends of resilient legs, said corner segments reciprocally movable between an outer position at which said corner segments engage said lip structure and an inner position at which said corner segments substantially disengage said lip structure whereby said retainer can be separated from said base.
 6. The apparatus of claim 1, wherein said retaining mechanism comprises a U-shaped spring having a pair of engagement legs interconnected by a bridging portion and further including elements by which pressure is applied to urge said leg portions towards each other in order to disengage portions of said spring from said lip structure, whereby said retainer part is released from said base part.
 7. The coupling device of claim 1 wherein said base has a plurality of tines projecting in an axial direction for piercing said pad.
 8. A snap together coupling device for mounting a floor maintenance pad to a drive disc on a power driven floor maintenance machine, comprising: a) a base attached to said drive disc and including an axially extending wall, said wall defining a lip structure extending radially inwardly from said wall; b) a retainer engageable with said base including alignment structure for aligning said retainer with said base as said retainer is installed on said base; and, c) a retaining element carried by said retainer and including portions engageable with said lip structure, such that said retaining element inhibits separation of said retainer from said base when said retaining element engages said lip structure.
 9. The coupling device of claim 8, wherein said retaining element comprises a U-shaped spring clip loosely held by a hub forming part of said retainer.
 10. The apparatus of claim 9, wherein said hub defines at least a portion of said alignment structure.
 11. The apparatus of claim 9, wherein said spring clip includes a pair of elongate legs that extend from a bridging section.
 12. The coupling device of claim 11, wherein said spring clip further comprises loops which define finger engageable pressure pads at ends of said elongate legs, such that squeezing said pressure pads urges said elongate legs towards each other in order to release the engagement between said spring clip and said lip structure.
 13. The coupling device of claim 8, wherein said retainer and base define a relatively large central opening through which floor treating fluids can be dispensed.
 14. A snap together coupling device for mounting a floor maintenance pad to a drive disc on a power driven floor maintenance machine, comprising: a) a first coupling member attached to, or forming part of, said drive disc; b) a second coupling member engageable with said first coupling member; c) one of said coupling members including alignment structure for aligning said second coupling member with said first coupling member as said second coupling member is installed on said first coupling member; d) one of said coupling members including an axially extending flange, said flange defining a lip structure extending radially inwardly from an inner wall of said axial flange; and, e) a retaining element carried by the other of said coupling members and including portions engageable with said lip structure, such that said retaining element inhibits separation of said first coupling member from said second coupling member when said retaining element engages said lip structure.
 15. The apparatus of claim 14 wherein said base portion is attached to said drive disc by suitable fasteners.
 16. The apparatus of claim 15 wherein said first coupling member comprises a base and said second coupling member comprises a retainer.
 17. The apparatus of claim 16 wherein said base includes an axial flange and said retainer carries said retaining element.
 18. A snap together coupling device for mounting a floor maintenance pad having a circular mounting hole to a drive disc on a power driven floor maintenance machine, the coupling device comprising: a) a base portion forming part of and having an axis of rotation substantially coincident with an axis of rotation of said drive disc; b) a retainer portion engageable with said base portion; c) one of said portions including an axially extending flange, said flange defining a lip structure extending radially inwardly from an inner wall of said axial flange; d) a retaining mechanism carried by the other of said portions and engageable with said lip structure, whereby said base portion is inhibited from separating from said retainer portion.
 19. The apparatus of claim 18 wherein one of said portions defines receiving structure for a hub defined by said other portion whereby said one portion is centered with respect to said other portion during installation.
 20. The apparatus of claim 19 wherein said retaining mechanism is carried by said retaining portion.
 21. The apparatus of claim 18 wherein said base portion is a separate member, secured to said drive disc.
 22. The apparatus of claim 18 wherein said base portion is integrally formed in said drive disc.
 23. The apparatus of claim 14 wherein said first coupling member is molded into said drive disc.
 24. The apparatus of claim 14 wherein said alignment structure comprises a hub. 